Convertible rail-highway tractor

ABSTRACT

A self-propelled vehicle or tractor with pneumatically tired wheels operable on roads or railroad tracks, especially useful for shunting railroad cars, which has a cradled drawbar works cooperating with a railroad car drawbar forming a rigid beam connection therewith and shiftable to exert a bending force on the rigid beam connection to transfer railroad car weight to a central portion of the vehicle for loading the wheels to increase the traction of the vehicle. Although the drawbar works project from an end of the vehicle beyond the wheels the loading force is transmitted by the bending beam action to a central portion of the vehicle for preventing tilting or vaulting of the vehicle.

United States Patent lnventor Robert F. Deike Cheyenne, Wyo.

Appl. No. 882,972

Filed Dec. 8,1969

Patented Jan. 11, 1972 Assignee Cleaner Container Corporation Cheyenne, Wyo.

CONVERTIBLE RAIL-HIGHWAY TRACTOR 20 Claims, 16 Drawing Figs.

Primary Examiner-Arthur L. La Point Assistant ExaminerHoward Beltran At!0rneyHill, Sherman, Meroni, Gross & Simpson ABSTRACT: A self-propelled vehicle or tractor with pneumatically tired wheels operable on roads or railroad tracks, especially useful for shunting railroad cars, which has a cradled drawbar works cooperating with a railroad car drawbar forming a rigid beam connection therewith and shiftable to exert a bending force on the rigid beam connection to transfer railroad car weight to a central portion of the vehicle for loading the wheels to increase the traction of the vehicle. Although the drawbar works project from an end of the vehicle beyond the wheels the loading force is transmitted by the bending beam action to a central portion of the vehicle for preventing tilting or vaulting of the vehicle.

PATENTED JAN] 1 m2 SHEET 1 [IF 5 PATENTED JAN? 1 i972 SHEET 2 BF 5 ales-33.514

PATENTEI] mu 1 I972 SHEET 3 BF 5 CONVERTIBLE RAIL-HIGHWAY TRACTOR BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to the art of tractors for propelling separately supported vehicles while using a portion of the vehicle weight to increase traction of the propelling force. More particularly, this invention relates to a shunting machine for railroad cars which can travel on roads or railroad tracks, has a revolvable table for facilitating transfer from a road to a railroad track, and has drawbar works which transfer railroad car weight to the machine frame without tilting the machine while loading the driving wheel of the machine to increase their traction grip with the railroad tracks.

2. Description ofthe Prior Art Heretofore, tractors or shunting machines for railroad cars have relied on dead weight to maintain necessary tractive capacity for propelling the load. Such heavy vehicles are not adapted for highway use, are expensive to manufacture and operate. Since their use is confined to railroad tracks, they cannot be transferred around obstacles on the tracks, and require track switches to be moved from one track to another.

SUMMARY OF THE INVENTION This invention now provides a rubber-tired, wheeled vehicle easily maneuvered on roads as well as railroad tracks, having turntable equipment facilitating transfer from roads to railroad tracks and a drawbar works which locks with a conventional railroad car coupler and is shifted relative to the vehicle frame for transferring a portion of the weight of the car to which is is coupled proportionally to the rubber-tired wheels for increasing their traction load on the tracks. Since the tractive force is borrowed from the weight of the railroad car to be propelled, the vehicle itself may be relatively light in weight, preferably has four pneumatic tire equipped wheels, including a pair of dirigible front wheels and a pair of internal combustion engine driven rear wheels. The tires and the wheels are large enough to lap around the railroad tracks, providing a V-groove pulley driving effect. Small flanged metal railroad car idler wheels are provided on the vehicle to be dropped in place on the tracks for guiding the rubber tires on the tracks.

The vehicle is equipped with a central turntable suspended from the frame between the front and rear wheels and having small flanged metal railroad car wheels. In road operation the turntable is raised, and in rail operation it is lowered to engage the wheels with the tracks for affording additional guidance and load-carrying capacity. To transfer the vehicle from a road to a railroad track, it is only necessary to straddle the vehicle across the track, aligning the turntable with the track, then lower the turntable to support the vehicle on the track and raise it to sufficient height for clearing the pneumatic tires above the track level, whereupon the turntable is then actuated to swing the vehicle into alignment with the track, and then the turntable is raised to lower the rubber tires onto the track.

The vehicle has a drawbar works cradled in the rear end thereof to couple with the conventional drawbar coupler of a railroad car. This drawbar works is supported at its rear end on radial arms pivotally carried at the rear end of the vehicle frame at a level below the axle of the driving wheels. The front end of the drawbar works is supported on rollers which ride in inclined channels that are pivoted on the vehicle frame above the driving wheel axle. Coil springs are compressed between the free ends of the channels and the vehicle frame rearwardly of the driving axle. A hydraulic ram pivotally connected between the vehicle frame ahead of the driving axle and the top rear end of the drawbar works is effective to swing the drawbar works about its radial arm pivots and channel-carried rollers to raise the drawbar works relative to the frame, while also shifting it rearwardly. The coupling between the drawbar works and the car coupler is such that this raising action will tend to lift the railroad car, causing the drawbar works to support a portion of the weight of the car. This weight is transferred back to the frame of the vehicle through the coil springs between the inclined channels and the frame, which are compressed as the channels are swung rearwardly and downwardly by the rollers riding therein when the drawbar works swings rearwardly and upwardly. The amount of initial loading of the vehicle frame from the railroad car is controlled by extension of the hydraulic ram which swings the drawbar works in its cradle support. In the initial transfer of weight load from the railroad car to the vehicle, the rollers in the channels are substantially vertically aligned with the driving axle of the vehicle, but as the loading is increased, these rollers move rearwardly of the axle. This action is facilitated by driving the vehicle to pull the railroad car to which it is coupled.

This pulling action in itself will swing the drawbar works to further load the vehicle frame, and when a desired load is reached, the hydraulic ram may be locked, whereupon a rigid beam lever connection is established between the railroad car and the vehicle frame.

The initial swinging of the drawbar works by the hydraulic ram depresses the vehicles springs, causing the vehicle frame to lower and pressing the driving tires tightly against the tracks. This, of course, is accomplished by raising the level of the drawbar works as it swings rearwardly. Once a rigid beam coupling effect is established between the car and the vehicle drawbar works, further raising of the drawbar works by hydraulic ram action then creates a lever arm action with an increasing moment as the rollers swing rearwardly from the axle. This moment is transferred with the axle as a fulcrum forwardly towards the front wheels of the vehicle, thereby preventing the vehicle from vaulting or tilting about its rear axle, and, or course, increasing the traction load on all of the vehicle wheels.

It is then an object of this invention to provide a prime mover for propelling separately supported loads which derive traction loading force from the propelled vehicle.

Another object of this invention is to provide a railroadshunting machine operable on loads and railroad tracks which has a drawbar works so cradled thereon as to transfer a portion of the weight of the railroad car being propelled to the drivers of the machine for increasing the traction capacity of the machine.

Another object of this invention is to provide a lightweight, pneumatically tired, wheeled vehicle operating both on roadways and on railroad tracks to move independently supported wheeled vehicles which has a hydraulically actuated coupler so supported thereon as to transfer a portion of the load of the separate-wheeled vehicle to the traction wheels, thereby increasing their traction capacity.

Another object of this invention is to provide a vehicle with a pair of rubber-tired driven wheels, a pair of rubber-tired steering wheels, a railroad wheel-carrying turntable between said driving and steering wheels, mechanism for raising and lowering the turntable to transfer the vehicle from a roadway to a railroad track, and a cradled drawbar works coupling with a railroad car drawbar to form a rigid lever beam and means for shifting the cradled drawbar works to transfer a portion of the load of the railroad car through said created beam into the vehicle between the driven and steering wheels for lowering the frame of the vehicle and increasing the tractive capacity of the vehicle on the railroad track.

Another object of this invention is to provide a pneumatically tired, wheeled shunting machine for railroad cars which is loaded from the weight of the car being propelled thereby to lap the tires around the railroad tracks and create a wedge pulley driving grip with the railroad tracks.

Another object of this invention is to provide a railroad car shunting machine adapted to travel on highways as well as railroad tracks and having a turntable mechanism facilitating mounting of the machine on a railroad track and facilitating removal of the machine from the railroad track to a roadbed.

Other and further objects of this invention will be apparent to those skilled in this art from the following detailed description of the annexed sheets of drawings, which, by way of a preferred example only, illustrate one embodiment of the invention, it being understood that many other embodimen ts are contemplated within the scope of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of the tractor or shunting machine of this invention;

FIG. 2 is a side elevational view of the chassis of the machine of FIG. 1;

FIG. 3 is a rear elevational view of the chassis of FIG. 2 taken along the line Ill-III of FIG. 2;

FIG. 4 is a plan view of the rear end of the chassis taken along the line IVIV OF FIG. 2;

FIG. 5 is a cross-sectional view taken along the line VV of FIG. 4 with parts in elevation;

FIG. 6 is a fragmentary cross-sectional view taken along the line VI-VI of FIG. 5;

FIG. 7 is an enlarged plan view of the midchassis truck for the turntable taken along the line VII-VII of FIG. 2;

FIG. 8 is a cross-sectional view taken along the line VII- VII of FIG. 7 and also showing the turntable on the truck;

FIG. 9 is a diagrammatic illustration of a portion of the tractor or shunting machine coupled with the drawbar of a railroad car and illustrating the position of the drawbar works of the tractor in an unloaded position immediately after being coupled with the drawbar of the railroad car;

FIG. 10 is a view similar to FIG. 9 but illustrating the position of the drawbar works when power is applied to the hydraulic ram forcing the railroad car drawbar against the top of its coupling box with only about one-third of the final load application of the weight of the railroad car being transmitted to the drawbar works;

FIG. 11 is a view similar to FIG. 10 but illustrating the positions of the parts after about two-thirds of the final load application has been applied;

FIG. 12 is a view similar to FIG. 11 but illustrating the relative positions of the parts after full load application.

FIG. 13 is a diagrammatic illustration of the lever arm actions and load moment transfer obtained in loading the vehicle from the railroad car to which it is coupled;

FIG. 14 is a lever arm diagram illustrating the manner in which the moment arm is increased to load the vehicle forwardly ofthe driving axle;

FIG. 15 is a hydraulic piping diagram of the loading rams on the vehicle;

FIG. 16 is a fragmentary cross-sectional view of a traction wheel on the track taken along the line XVIXVI of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT The tractor or shunting machine 10 of FIG. 1 has a central cab 11 with a forwardly projecting engine hood 12 and a rearwardly projecting drawbar works hood 13. The machine has a pair of pneumatic, rubber-tired front steering wheels 14 and a pair of similarly tired rear driving wheels 15. Small metal railroad idler wheels 16 are mounted in front of the steering wheels 14, and similar idler wheels 17 are mounted rearwardly of the driving wheels 15. A turntable 18 is suspended under the vehicle 10 between the front wheels 14 and rear wheels 15 and carries two pairs of railroad idler wheels 19. The wheels 14 and 15 are equally adapted to ride on a roadbed or a railroad track, while the wheels 16, 17, and 19 are placed in operation only when the vehicle is operating on a railroad track.

A conventional railroad car coupling drawbar 20 is mounted on the front end of the vehicle 10 ahead of a winch 21. A coupler 22 projects rearwardly from the vehicle from the drawbar works mounted under the hood 13, as will be more fully hereinafter described.

As shown in FIG. 2, the machine 10 has a chassis ported by springs 27, respectively.

23 sup- 24 and 25 from front and rear axles 26 and The chassis 23 extends forwardly beyond the front wheels 14, which are dirigible wheels, and rearwardly beyond the rear wheels 15, which are driven wheels. An internal combustion engine 28 is supported by the chassis 23, preferably forwardly of the front axle 26 to provide front end weight for the vehicle. The engine operates through a conventional transmission and propeller shaft to drive the rear axle 27 and wheels 15.

The rear end of the chassis 23 supports a generally U- shaped vertical frame 29 with a horizontal cross-shaft 30 about the level of the axle 27. Radial arms or links 31 are pivoted on this cross-shaft 30, extending upwardly between the side beams of the chassis 23 and straddling the mounting frame or box 32 of the drawbar works 33. The upper ends of these arms 31 are pivotally connected to the sidewalls of the box 32 at the top rear corners thereof by means of tubular bearings 34, which are welded to the sides of the box and project laterally outward therefrom.

The rear upper corners of the box 32 have rigid axles projecting laterally therefrom with rollers 35 on their ends riding in channel beams 36 which are pivoted at their bottom ends to the side beams of the chassis 23 on laterally projected horizontal pivots 37. As shown, the pivots 37 are welded to the rear sidewalls of the channel beams immediately adjacent the bottom ends of the beams. The rollers ride in the beams which have their open sides facing the sidewalls of the box 32.

The free ends of the channel beams 36 have bosses 38 depending from the rear sides thereof. Similar bosses 39 are welded on the outer side faces of the side beams of the chassis 23, and heavy compression coil springs 40 are seated at their ends around these bosses 38 and 39.

The box or support 32 of the drawbar works 33 is thus pivotally supported at its rear upper corners through the bearings 34 on the links or arms 31, and is supported at its front upper corner from the channel beams 36 through the rollers 35, with the springs 40 urging the channel beams 36 to upright, forward positions.

A hydraulic ram 41 has its cylinder portion 42 pivotally mounted on a crossbeam or tube 43 carried by the chassis 23 forwardly of the rear axle 27. The piston rod 44 of the hydraulic ram 41 is pivotally connected to an upstanding bracket 45 on the top of the box 32 about midway between the sidewalls of the box. This ram 41 is effective to swing the box 32 of the drawbar works on the links or arm supports 31 about the fixed pivots 30 of these arms, and on the rollers 35 about the fixed pivots 37 of the channel beams 36. In the retracted position of the ram 41, the box 32 is in a substantially horizontal position between the side beams of the chassis 23 and forwardly of the rear end U-shaped frame 29. In this position the channel beams 36 are substantially upright and the rollers 35 will be at the bottom ends of these channel beams 36, while the links or radius arms 31 will extend upwardly and rearwardly from their pivots 30. In this position the springs 40 are in their expanded condition. It will also be understood that as the ram 41 is elongated, the box 32 is swung rearwardly and upwardly about its fixed pivots 30 and 37, moving the rollers 35 upwardly and rearwardly in the channels 36 and compressing the springs 40. These springs 40 provide relief or escapement between the rigidly loaded beam connection with the railroad car and cooperate with the vehicle springs 24 to allow rise and fall of the vehicle without overloading or releasing the railroad car load on the vehicle, thereby maintaining traction without unduly stressing the tractor. As will be hereinafter pointed out, this suspension of the drawbar works 33 is effective to transfer loads from the car to be propelled to the chassis 23 without tilting the chassis.

As shown in FIGS. 4 and 5, the rear coupler 22 has a drawbar 46 extending into the box 32 of the drawbar works and mounted therein for sliding movement. A crossbar tongue 47 extends transversely across the box 32 and through a slot near the front end of the drawbar 46.

Four compression springs 48 are positioned between the tongue 47 and the front and rear ends of the box 32. The front and rear springs 48 are mounted along each side of the drawbar 47. The springs act to center the drawbar in the box and are compressed to transfer either a pulling or pushing load from the coupler 22 to the box 32.

The drawbar preferably rests on a row of ball bearings 49 carried in a channel mounting 50 in the box under the drawbar adjacent the rear end of the box. The ball bearings accommodate free transverse swinging movements, as well as front and rear movement ofthe coupler 22.

The coupler 22, drawbar 46 and drawbar works, including the box 32, the spring mountings, etc., are standard. A plate 51 is welded to the bottom of the coupler 22 and projects horizontally rearward therefrom to provide a stop, as will be hereinafter more fully described.

As shown in FIG. 9, a railroad car C is coupled with the coupler 22 and has the standard spring-mounted drawbar 52 terminating in a coupler end 53. The couplers 22 and 53 are equipped with the standard tongues (not shown) uniting them in interlocked position. The drawbar 52 is slidably mounted in a drawbar box 54 secured to the bottom of the car C. When the drawbar works 33 of the machine are raised by the ram 41, the plate 51 will engage the bottom of the coupler 53 to apply a lifting action on the car C through the drawbar 52. The load will be borne by the ball bearings 49 in the drawbar box 32, and, of course, transmitted through the box and links to the chassis 23 ofthe machine 10.

As shown in FIG. 3, the bottom of the U-shaped frame 29 has brackets 55 projecting rearwardly therefrom and supporting a cross-tube 56 on the ends of which are swingably mounted, rearwardly projecting arms 57 carrying the axles for the car wheels 17.

Similarly, as shown in FIG. 2, a subframe structure 58 depending from the front end of the chassis 23 ahead of the wheels 14 supports a cross-tube 59, on the ends of which are swingably mounted, rearwardly extending arms 60 carrying the axles for the front guide wheels 16.

Spring loaded pairs of hydraulic rams 61 and 62, respectively pivotally suspended from the subframe 58 at the front end of the chassis and from the rear end of the chassis, urge the wheels 16 and 17 downwardly under the spring force therein, but are effective to raise the wheels above the ground-engaging levels of the wheels 14 and by actuating the pistons in the rams to compress the springs therein.

The turntable construction 18, as shown in FIGS. 2, 7 and 8, includes a table 63 suspended from vertical hydraulic jacks 64 depending from the central portion of the chassis 23. The table 63 has a ring of rollers 65 depending from the bottom face thereof, and these rollers ride on the rim of a wheellike turntable 66. An electric motor 67 on the table 63 drives a ring gear 68 effective to rotate the table 63 relative to the table 66.

As shown in FIG. 8, the table 63 has a central depending tapered stud axle 69 rotatable in a central bearing 70 of the table 66. When the gear 68 is driven, the table 63 will rotate on the table 66, with the rollers riding on the rim of the table 66, as shown in FIG. 8. Relative rotation of the two tables 63 and 66 will, of course, swing the chassis 23 about the turntable 66.

The turntable 66 carries an I-beam framework 71 composed of short I beams 72 straddling and secured to the turntable 66 and longer l-beams 73 carried by the ends of the beams 72 and of sufficient length to extend across and beyond railroad tracks R of standard gauge. The outer ends of these I-beams 73 have spaced parallel beams 74 slidably mounted thereunder and extending across the space between the beams 73. These beams 74 are suspended from the beams 73 on rods 75 carried at their ends in brackets 76 depending from the bottoms of the beams 73. Pillow block bearings 77 are secured to the bottom faces of the beams 74 and support axles 78 for the rail wheels 19. Springs 79 on the rods 75 are compressed between the beams 74 and the end brackets 76, and serve to center the beams 74 at a gauge width for straddling the railroad tracks R.

It will, therefore, be understood that truck mountings for the wheels 19 are slidably mounted under the beams 73 and are centered by the springs 79, which, of course, will accommodate shifting of the trucks so that the wheels can remain on the tracks R when rounding curves and the like.

The jacks 64, of course, are effective to raise the turntable 18 off of the tracks R, as when the vehicle is traveling down a road, and to lower the turntable so that the wheels 19 will rest on the tracks R when the vehicle is on the tracks.

To transfer the vehicle or machine 10 from a roadbed to the tracks R, it is only necessary to drive the vehicle crosswise of the tracks and align the wheels 19 with the tracks, whereupon the jacks 64 force the turntable 18 downwardly to engage the wheels 19 with the tracks and raise the vehicle to a level where the wheels 14 and 15 can swing over the tracks. Then the motor 67 is actuated to drive the turntable and rotate the vehicle into alignment with the tracks, whereupon the jacks again lower the vehicle onto the tracks so that the tires on the wheels 14 and 15 will lap around the tracks, as shown in FIG. 16. As therein shown, the tires are V-grooved by the tracks to form a wedge pulley drive with the tracks.

FIGS. 9-12 illustrate, somewhat diagrammatically, the action of the drawbar works 33 and the reaction on the frame 23 of the machine or vehicle 10 during the various stages of loading the vehicle and illustrating the relative positions of the parts during the loading steps.

In FIG. 9 the drawbar works 33 is illustrated in an unloaded position immediately after being coupled with the drawbar 52 of the railroad car C. At this stage the plate 51 underlies the coupler 53 of the railroad car C in tight abutting relation. The ram 41 is in its contracted condition, the channel beams 36 are substantially upright, the springs 40 are relaxed and extended, and the radial arms 31 are in their foremost inclined position. The rollers 35 are at the bottom ends of the inclined channels 36, and the box or body 32 of the drawbar works is cradled in the chassis 23, with its top edge projecting thereabove a distance illustrated at D. The axle 27 of the vehicle 10 is below and just rearward of the rollers 35 and about directly under the pivot 37 for the inclined channels 36.

As shown in FIG. 10, when power is applied to the ram 41, the drawbar works is shifted rearwardly and upwardly relative to the chassis 23, but since the plate 51 between the locked couplers 22 and 53 prevents raising of the drawbar works 33 relative to the car drawbar 52, this drawbar 52 is forced tightly against the top of its box 54 and a portion of the weight of the car C is transmitted to the drawbar works 33, causing the chassis 23 to be forced downwardly, increasing the distance between the top of the drawbar works and the chassis, as indicated at D,. This downward movement is accommodated by depression of the springs of the vehicle and, of course, positions the chassis closer to the axle 27. It will also be noted from FIG. 10 that the roller 35 has started to climb in the channel beam 36, forcing the beam rearwardly and compressing the spring 40. The radial arm 31 also is swung rearwardly. A rigid lever couple is thereby established between the car C and the drawbar works 23. FIG. 10 illustrates the positions of the parts at about 3 3 percent load application.

FIG. 1 1 illustrates the positions of the parts at about 66 percent load application, with the radial arm 31 approaching a vertical position, and with the chassis 23 being further depressed, as illustrated by the gap D between the top of the drawbar box 32 and the top of the chassis frame. As shown, the roller 35 is approaching the top end of the inclined channel beam 36, which is tilted rearwardly and downwardly, and the spring 40, of course, is further compressed. The roller 35 has now moved to a position rearwardly of the axle 27.

In FIG. 12, the relative position of the parts are illustrated at l00 percent load application, and here the ram 41 is in its fully extended position, with the channel beam 36 approaching a horizontal position and with the roller 35 at the free end of the channel beam. The spring 40, of course, is fully compressed, and it will be especially noted that the roller 35 is now substantially rearward of the axle 27. The radial arm 31 is in an upright position, and the drawbar works 33 has assumed its greatest projection D above the chassis 23, meaning, of course, that the vehicle springs have been further depressed to their maximum degree.

It should be understood from FIGS. 9l2 that the coupledtogether drawbars create an elongated beam uniting the car C and the chassis 23. Considering the car C as the fixed end for this beam and the axle 27 of the vehicle 10 as a fulcrum, it will be understood that any upward loading of the beam between the axle and the car will tend to bend it, creating a downward thrust or moment ahead of the axle 27 and forcing the entire chassis 23 downward.

FIGS. 13 and 14 illustrate the bending beam action of the rigid beam connection established between the chassis of the tractor or shunting machine and the railroad car through the coupled drawbars thereof. In FIG. 13 the reference numeral 30 illustrates an initial lever arm established between the loaded drawbar 52 and the railroad car at point C and the roller 35 at the start of the loading operation described in connection with FIG. 9. Under these conditions the roller 35 is substantially directly over the axial 27 and the least weight is placed on the vehicle. The reference numeral 81 illustrates the fully loaded lever arm when full load is applied and the parts assume the positions of FIG. 12. Under these conditions the roller 35 is considerably rearward of its starting position and the lever arm 81 is shorter than the initial lever 80. The horizontal shift from initial roller position and the fully loaded roller position is illustrated by he line 80a between the position A representing the initial position of the roller 35 and the position B representing the displaced fully loaded position of the roller 35.

The line 81a represents a lever arm between the roller 35 in its unloaded position at point A and the pivot support 30 for the radial arms or links 31 in their unloaded position.

Then, as illustrated in FIG. 14, the initial rigid beam 80, shown in solid lines, extends from the point C to the position A of the roller. Then, when the vehicle is pulled away from the car C, the pivot support 30 for the radial arm 31 is pulled forwardly or conversely, the drawbar works may be viewed as being shifted rearwardly a distance illustrated at 300, and the resulting upright or less inclined radial arm creates a bending action on the lever arm 80 causing it to have an upward reaction as illustrated in dotted lines. At the same time, however, as the vehicle frame is drawn to the left from under the drawbar works 33 or as the drawbar works is shifted rearwardly of the vehicle, the roller 35 moves from its position A to its position B establishing an increased downward load on the bent beam placing the radial arm 31 in tension and tending to swing the rear of the vehicle upwardly. This, of course, puts a thrust load into the central portion of the vehicle ahead of the axle 27 causing the vehicle to squat down on the tracks.

It should, therefore, be understood that the rigid beam created by the locked couplers make use of the anchor point afforded by the weight of the railroad car C and a shifting of the drawbar works to create the downward moment arm ahead of the axle 27 so that the vehicle will not vault or tilt about the axle to raise the front end thereof.

In the piping diagram of FIG. 15, a pump 82 driven by the motor 28 supplies fluid under pressure to the various rams through suitable valves and tubes. The rams 61 and 62 are only single acting against the springs therein, while the rams 41 and 64 are, of course, double acting. Fluid from a tank 83 supplies the pump 82 which feeds valves 84, 85, and 86. The valves 84 and 85 are operated to supply pressure fluid from the pump to a selected end of the rams 41 or 64, which they control, and to release fluid from the opposite ends of these rams to the tank 83. The valve 86 feeds pressure fluid to the bottoms of the rams 61 and 62, compressing the springs to raise the wheels 16 and 17, or releases the fluid to the tank 83 to allow the springs to force the wheels against the tracks. While only a pair of rams 64 and a pair of rams 61 and 62 are shown, four such rams can be provided.

As shown in FIG. 16, the tire 87 on the wheel 15 will lap over the railroad track R to form a V-groove 88 which has a wedge drive gripping action on the track R. This wedge groove 88 is deepened under the increased load applied by the loading ram 41 From the above descriptions it will, therefore, be understood that this invention provides a self-propelled, wheeled vehicle which will propel a separate wheeled vehicle and derive traction or load from the separate vehicle without ever carrying this vehicle. The degree of load is controlled by the shifting of a drawbar works which can be regulated hydraulically and is transferred by a beam effect to create a bending lever which will maintain the vehicle against the roadbed or against railroad tracks with the desired tractive loading force. It will also be understood that the vehicle of this invention is easily transferred from a road to a railroad track and can have two, four, or more rubber-tired driving wheels.

It will further be understood that the pulling of the vehicles coupled therewith will assist the hydraulic ram 41 in loading the vehicle to obtain the tractive force. However, the vehicles of this invention are also adapted to push the vehicle to which they are coupled, and in such event the actuating ram 41 is activated until the desired tractive load is obtained, and then the ram is locked.

I claim as my invention:

1. A tractor adapted to shunt railroad cars which comprises a resilient tire-supported vehicle, a drawbar works cradled in said vehicle having a car coupler projecting from one end of the vehicle effective to couple with a drawbar of a railroad car and create a rigid beam connection therewith, means actuated by a pulling force on said drawbar works to exert a bending action on said rigid beam connection with a downward moment centrally of the vehicle to increase the tractive load on the resilient tires without tilting the vehicle, and pressure relief means between the rigid beam and the resilient tires.

2. The tractor of claim 1 wherein the drawbar works includes a box, a drawbar pivotally and slidably mounted in the box and having a car coupler on the end thereof projecting rearwardly from the vehicle, radial arms pivoted on the vehicle straddling said drawbar box and pivotally connected to the upper rear ends thereof, beams pivoted on the vehicle, rollers mounted on the forward upper ends of said drawbar box riding in said beams, a hydraulic ram pivoted to the top of said box at the forward end thereof for swinging the box about the radial arms causing the rollers to lower the beams, and spring means between the vehicle and the beams compressed by the lowering of the beams.

3, The tractor of claim 1 wherein the pressure relief means are spring means compressed by the bending action on the rigid beam connection acting on the vehicle.

4. The tractor of claim 1 including railroad idler wheels coacting with the resilient tires for mounting the vehicle on a railroad track.

5. The tractor of claim 4 wherein means are provided on the vehicle to selectively raise and lower said idler wheels.

6. A tractor for moving a separately supported vehicle while deriving additional traction force from the vehicle which comprises a wheeled chassis having driving wheels, a coupler cradled in one end of the chassis to swing to different heights relative to the chassis, means on the coupler effective to couple with a drawbar of a railroad car to create a rigid beam connection therewith, means accommodating shifting of the cradled coupler relative to the chassis to exert a bending action on the rigid beam connection for transferring weight from the railroad car centrally of the chassis and means on the chassis for swinging said cradled coupler relative to the chassis and effective to control the magnitude of the transferred weight to the chassis without overloading or tilting the tractor.

7. The tractor of claim 6 wherein the cradle mounting for the coupler includes a pair of link arms depending from the rear end of the coupler, a pivot support for said link arms on the vehicle below the coupler, and cooperating roller and spring loaded channel beams on the coupler and the vehicle for loading the vehicle when the link arms are swung rearwardly of the vehicle.

8. The tractor of claim 6 wherein the coupler has a plate on the bottom end thereof for lifting the vehicle to which it is coupled.

9. The tractor of claim 6 wherein the vehicle has a driving motor on the end thereof remote from said coupler effective to counterbalance the vehicle against tilting.

10. The tractor of claim 6 wherein the means transferring weight ofthe vehicle to the chassis includes a hydraulic ram.

11. The tractor of claim 6 wherein the means on the coupler transferring weight from the vehicle to be moved to the chassis ahead of the driving wheels include channel beams pivoted on the vehicle, springs holding the channel beams in upright position, and rollers between the coupler and channel beams effective to tilt the channel beams for compressing the springs.

12. A shunting machine which comprises a wheeled vehicle having rubber-tired, ground-engaging wheels and flanged railroad car idler wheels, means for selectively raising and lowering said idler wheels for guiding the rubber-tired wheels on a railroad track when lowered and for separation from a roadbed when raised, a turntable suspended from the central portion of said vehicle having rail-engaging wheels and mechanism for raising and swinging the vehicle onto railroad tracks, a drawbar works cradled in one end of said vehicle having a car coupler extending from said end, hydraulic power means shifting said drawbar works to exert a lifting action on said coupler, said coupler having locking means interlocking with a railroad car drawbar to establish a rigid beam connection between the vehicle and railroad car, and means translating lifting action of the drawbar works to exert a bending action on said rigid beam connection creating a downward force movement loading the wheels of the vehicle against the railroad track and effective to form a wedge groove pulley drive between the tires and railroad track.

13. A shunting machine which comprises a vehicle having a pair of pneumatic rubber-tired front steering wheels and a pair of pneumatic rubber-tired rear driving wheels, the wheels of each pair having a gauge width for riding on a railroad track, a railcar wheel-equipped turntable suspended from said vehicle between the front and rear pneumatically tired wheels thereof, mechanism for lowering said turntable to raise the vehicle above the level of railroad tracks, mechanism for rotating the vehicle on said turntable to mount the vehicle on the railroad tracks, spring-urged railroad car idler wheels suspended from the vehicle in front of the front wheels and in back of the rear wheels effective for guiding the rubber-tired wheels on a railroad track, a drawbar works cradled in said vehicle above the rear tired wheels and having a drawbar with a coupler on the end thereof projecting rearwardly beyond the vehicle to lock with a railroad car drawbar and create a rigid beam connection therewith, and a hydraulic ram swinging said drawbar works relative to the vehicle for exerting a bending action on said rigid beam connection effective to press the pneumatic tires of the vehicle into lapped relation with the track forming a V-grooved pulley drive connection therewith.

14. A railroad car shunting machine adapted to travel on highways and on railroad tracks which comprises a vehicle having four pneumatically tired wheels, including a pair of steering wheels and a pair of driving wheels, a turntable suspended from the vehicle between the steering wheels and the driving wheels, power means for raising and lowering the turntable for raising the vehicle and the tired wheels off of a road and for lowering the vehicle and tired wheels onto a railroad track, and power means for swinging the vehicle on the lowered turntable to align the tired wheels with a railroad track for transferring the vehicle from a road to a railroad track.

15. The shunting machine of claim 14 wherein the turntable has a pair of spring-centered wheel-carrying trucks riding on the railroad tracks.

16. The shunting machine of claim means for swinging the vehicle on the motor. I

17. In a railroad tractor vehicle, a drawbar box cradled in the rear end of said vehicle for fore and aft swinging movement, a coupler projecting from said box, means connecting said coupler with said box accommodating swinging movement of the coupler laterally of the vehicle and fore and aft projection and retraction relative to the box, means on said coupler effective to lock with a drawbar coupler of a railroad car for creating a rigid beam connection therewith, and means translating said swinging movement of said drawbar box to exert a bending action on said rigid beam connection to transfer weight from the railroad car into a downward thrust force on the vehicle beyond the end of the drawbar box which is remote from the railroad car.

18. The railroad tractor vehicle of claim 17 having a driving motor mounted on the front end of the vehicle to counterbalance weight transferred to the rear end of the vehicle from the railroad car.

19. A shunting machine adapted to travel on railroad tracks and on highways which comprises a pneumatically tired wheeled vehicle including steering wheels and driving wheels, a drawbar works suspended on the vehicle projecting longitudinally beyond the driving wheels of the vehicle including a coupler effective to lock with coupler on the drawbar of a railroad car to form a rigid beam connection therewith, and means shifting said drawbar works relative to said vehicle for exerting a bending action on the rigid beam connection with the railroad car drawbar effective to press the tires of the driving wheels into lapped engagement with the railroad tracks.

20. A shunting machine adapted to travel on highways and railroad tracks which comprises a pneumatically tired vehicle having driving wheels at one end thereof and steering wheels at the other end thereof, an engine on said other end of the vehicle driving the drive wheels at said one end of the vehicle, a drawbar works cradled in said one end of the vehicle having a coupler projecting therefrom for coupling with the coupler on the drawbar of a railroad car to establish a rigid beam con nection therewith, and hydraulic power means on said vehicle shifting said drawbar works relative to the vehicle to exert a bending action on said rigid beam connection effective to create a downward thrust force between the driving wheels and steering wheels for increasing the traction drive of the driving wheels without lifting the steering wheels.

14 wherein the power turntable is an electric 

1. A tractor adapted to shunt railroad cars which comprises a resilient tire-supported vehicle, a drawbar works cradled in said vehicle having a car coupler projecting from one end of the vehicle effective to couple with a drawbar of a railroad car and create a rigid beam connection therewith, means actuated by a pulling force on said drawbar works to exert a bending action on said rigid beam connection with a downward moment centrally of the vehicle to increase the tractive load on the resilient tires without tilting the vehicle, and pressure relief means between the rigid beam and the resilient tires.
 2. The tractor of claim 1 wherein the drawbar works includes a box, a drawbar pivotally and slidably mounted in the box and having a car coupler on the end thereof projecting rearwardly from the vehicle, radial arms pivoted on the vehicle straddling said drawbar box and pivotally connected to the upper rear ends thereof, beams pivoted on the vehicle, rollers mounted on the forward upper ends of said drawbar box riding in said beams, a hydraulic ram pivoted to the top of said box at the forward end thereof for swinging the box about the radial arms causing the rollers to lower the beams, and spring means between the vehicle and the beams compressed by the lowering of the beams.
 3. The tractor of claim 1 wherein the pressure relief means are spring means compressed by the bending action on the rigid beam connection acting on the vehicle.
 4. The tractor of claim 1 including railroad idler wheels coacting with the resilient tires for mounting the vehicle on a railroad track.
 5. The tractor of claim 4 wherein means are provided on the vehicle to selectively raise and lower said idler wheels.
 6. A tractor for moving a separately supported vehicle while deriving additional traction force from the vehicle which comprises a wheeled chassis having driving wheels, a coupler cradled in one end of the chassis to swing to different heights relative to the chassis, means on the coupler effective to couple with a drawbar of a railroad car to create a rigid beam connection therewith, means accommodating shifting of the cradled coupler relative to the chassis to exert a bending action on the rigid beam connection for transferring weight from the railroad car centrally of the chassis and means on the chassis for swinging said cradled coupler relative to the chassis and effective to control the magnitude of the transferred weight to the chassis without overloading or tilting the tractor.
 7. The tractor of claim 6 wherein the cradle mounting for the coupler includes a pair of link arms depending from the rear end of the coupler, a pivot support for said link arms on the vehicle below the coupler, and cooperating roller and spring loaded channel beams on the coupler and the vehicle for loading the vehicle when the link arms are swung rearwardly of the vehicle.
 8. The tractor of claim 6 wherein the coupler has a plate on the bottom end thereof for lifting the vehicle to which it is coupled.
 9. The tractor of claim 6 wherein the vehicle has a driving motor on the end thereof remote from said coupler effective to counterbalance the vehicle against tilting.
 10. The tractor of claim 6 wherein the means transferring weight of the vehicle to the chassis includes a hydraulic ram.
 11. The tractor of claim 6 wherein the means on the coupler transferring weight from the vehicle to be moved to the chassis ahead of the driving wheels include channel beams pivoted on the vehicle, springs holding the channel beams in upright position, and rollers between the coupler and channel beams effective to tilt the channel beams for compressing the springs.
 12. A shunting machine which comprises a wheeled vehicle having rubber-tired, ground-engaging wheels and flanged railroad car idler wheels, means for selectively raising and lowering saId idler wheels for guiding the rubber-tired wheels on a railroad track when lowered and for separation from a roadbed when raised, a turntable suspended from the central portion of said vehicle having rail-engaging wheels and mechanism for raising and swinging the vehicle onto railroad tracks, a drawbar works cradled in one end of said vehicle having a car coupler extending from said end, hydraulic power means shifting said drawbar works to exert a lifting action on said coupler, said coupler having locking means interlocking with a railroad car drawbar to establish a rigid beam connection between the vehicle and railroad car, and means translating lifting action of the drawbar works to exert a bending action on said rigid beam connection creating a downward force movement loading the wheels of the vehicle against the railroad track and effective to form a wedge groove pulley drive between the tires and railroad track.
 13. A shunting machine which comprises a vehicle having a pair of pneumatic rubber-tired front steering wheels and a pair of pneumatic rubber-tired rear driving wheels, the wheels of each pair having a gauge width for riding on a railroad track, a railcar wheel-equipped turntable suspended from said vehicle between the front and rear pneumatically tired wheels thereof, mechanism for lowering said turntable to raise the vehicle above the level of railroad tracks, mechanism for rotating the vehicle on said turntable to mount the vehicle on the railroad tracks, spring-urged railroad car idler wheels suspended from the vehicle in front of the front wheels and in back of the rear wheels effective for guiding the rubber-tired wheels on a railroad track, a drawbar works cradled in said vehicle above the rear tired wheels and having a drawbar with a coupler on the end thereof projecting rearwardly beyond the vehicle to lock with a railroad car drawbar and create a rigid beam connection therewith, and a hydraulic ram swinging said drawbar works relative to the vehicle for exerting a bending action on said rigid beam connection effective to press the pneumatic tires of the vehicle into lapped relation with the track forming a V-grooved pulley drive connection therewith.
 14. A railroad car shunting machine adapted to travel on highways and on railroad tracks which comprises a vehicle having four pneumatically tired wheels, including a pair of steering wheels and a pair of driving wheels, a turntable suspended from the vehicle between the steering wheels and the driving wheels, power means for raising and lowering the turntable for raising the vehicle and the tired wheels off of a road and for lowering the vehicle and tired wheels onto a railroad track, and power means for swinging the vehicle on the lowered turntable to align the tired wheels with a railroad track for transferring the vehicle from a road to a railroad track.
 15. The shunting machine of claim 14 wherein the turntable has a pair of spring-centered wheel-carrying trucks riding on the railroad tracks.
 16. The shunting machine of claim 14 wherein the power means for swinging the vehicle on the turntable is an electric motor.
 17. In a railroad tractor vehicle, a drawbar box cradled in the rear end of said vehicle for fore and aft swinging movement, a coupler projecting from said box, means connecting said coupler with said box accommodating swinging movement of the coupler laterally of the vehicle and fore and aft projection and retraction relative to the box, means on said coupler effective to lock with a drawbar coupler of a railroad car for creating a rigid beam connection therewith, and means translating said swinging movement of said drawbar box to exert a bending action on said rigid beam connection to transfer weight from the railroad car into a downward thrust force on the vehicle beyond the end of the drawbar box which is remote from the railroad car.
 18. The railroad tractor vehicle of claim 17 having a driving motor mounted on the front end of the vehicle to counterbalance weight transFerred to the rear end of the vehicle from the railroad car.
 19. A shunting machine adapted to travel on railroad tracks and on highways which comprises a pneumatically tired wheeled vehicle including steering wheels and driving wheels, a drawbar works suspended on the vehicle projecting longitudinally beyond the driving wheels of the vehicle including a coupler effective to lock with coupler on the drawbar of a railroad car to form a rigid beam connection therewith, and means shifting said drawbar works relative to said vehicle for exerting a bending action on the rigid beam connection with the railroad car drawbar effective to press the tires of the driving wheels into lapped engagement with the railroad tracks.
 20. A shunting machine adapted to travel on highways and railroad tracks which comprises a pneumatically tired vehicle having driving wheels at one end thereof and steering wheels at the other end thereof, an engine on said other end of the vehicle driving the drive wheels at said one end of the vehicle, a drawbar works cradled in said one end of the vehicle having a coupler projecting therefrom for coupling with the coupler on the drawbar of a railroad car to establish a rigid beam connection therewith, and hydraulic power means on said vehicle shifting said drawbar works relative to the vehicle to exert a bending action on said rigid beam connection effective to create a downward thrust force between the driving wheels and steering wheels for increasing the traction drive of the driving wheels without lifting the steering wheels. 